1. Field of the Invention
The present invention relates to an electric vacuum cleaner and to a nozzle unit for an electric vacuum cleaner.
2. Description of the Prior Art
A conventional electric vacuum cleaner has a structure as shown in FIG. 48. A nozzle unit 8 having a nozzle (not shown) formed in its bottom surface is coupled to an extension pipe 6. The extension pipe 6 is coupled through a coupling member 2 to a flexible hose 3. The hose is coupled to the body 9 of the electric vacuum cleaner. The flow of air sucked in through the nozzle flows through the extension pipe 6, the coupling member 2, and the hose 3, and then reaches the body 9 of the electric vacuum cleaner, thereby achieving suction of dust.
The coupling member 2 has a handle 1 formed integrally therewith, which is held by the user during cleaning. The coupling member 2 also has an operation switch 10, which is used during cleaning to control a rotary brush (not shown) provided in the nozzle unit 8 and to control the body 9 of the electric vacuum cleaner.
The nozzle unit 8 is shown in more detail in FIG. 49. The nozzle unit 8 has a body case 32, of which a coupling portion 32a supports a first pipe 35 in such a way that the first pipe 35 is rotatable in the direction indicated by the arrow J1. The first pipe 35 supports a second pipe 36 in such a way that the second pipe 36 is rotatable in the direction indicated by the arrow J2. The above-mentioned extension pipe 6 is coupled to this second pipe 36.
Thus, the first pipe 35 allows the elevation (depression) angle of the extension pipe 6 to vary when the nozzle unit 8 is moved in the direction indicated by the arrow G. For example, the first pipe 35 is rotated in the direction J1 so that the extension pipe 6 becomes substantially upright, and then the second pipe 36 is rotated in the direction J2. Thus, the second pipe 36 allows the elevation (depression) angle of the extension pipe 6 to vary when the nozzle unit 8 is moved in the direction indicated by the arrow H.
On the two side surfaces of the coupling portion 32a of the body case 32, casters 39 are provided that roll on the floor so as to allow the nozzle unit 8 to move. The air sucked in in the direction indicated by the arrow F1 through the nozzle (not shown) formed in the bottom surface of the body case 32 flows in the direction indicated by the arrow F2 toward the coupling portion 32a. The air then flows through the first and second pipes 35 and 36 as indicated by the arrows F3, F4, and F5, then flows through the extension pipe 6, and then reaches the electric vacuum cleaner body 9.
In ordinary cleaning, as shown in FIG. 50, the first and second pipes 35 and 36 are kept in a straight line as seen from above, and cleaning is performed as the nozzle unit 8 is moved in the direction indicated by the arrow G. In cleaning of a narrow area such as a gap between pieces of furniture, as shown in FIG. 51, the second pipe 36 is rotated, and dust suction is performed as the nozzle unit 8 is moved in the direction indicated by the arrow H.
In an electric vacuum cleaner of this type, the handle 1 is fixed to the coupling member 2 so as to be integral therewith. Therefore, in cleaning of an area such as a gap below a bed, the user needs to take a low position to hold the handle 1 while moving the nozzle unit 8. This imposes an undue burden on the user, and is thus undesirable in terms of user-friendliness.
In some cases, to perform dust suction in a narrow area, an auxiliary nozzle is used, such as a crevice nozzle having a flat tip or a dusting brush having a brush at its tip. In such cases, first, the extension pipe 6 needs to be removed from the coupling member 2. Then, an auxiliary nozzle (not shown) stored inside the electric vacuum cleaner body 9 needs to be taken out and coupled to the coupling member 2 so as to be ready for use. This requires complicated handling, and is thus undesirable in terms of user-friendliness. There is also a possibility of loss of an auxiliary nozzle.
Handling of an auxiliary nozzle can be simplified if the auxiliary nozzle is removably held on the extension pipe 6. However, this requires the auxiliary nozzle to be kept visible with dust and the like clung to the tip thereof, and thus spoils the appearance. There is also a possibility of loss of an auxiliary nozzle as in the cases described previously.
Moreover, from the nozzle unit 8, the coupling portion 32a and the first and second pipes 35 and 36 protrude in the direction (indicated by G) of the depth of he nozzle unit 8. (Note here that a depth means the length of the shorter sides of something perpendicular as seen in a plan view.) Thus, the nozzle unit 8 has an unduly large depth W1 relative to the depth W2 of the nozzle 32b (see FIG. 51). This makes cleaning of a gap difficult, and also, by requiring the nozzle unit 8 to be made larger and thus heavier, imposes an undue burden on the user.
Moreover, the air passage is bent in the first pipe 35 and also in the second pipe 36, and thus the suction pressure suffers a great loss. This reduces suction efficiency and increases noise. Furthermore, the range of rotation of the first pipe 35 in the direction J1 is so narrow that the elevation (depression) angle of the extension pipe 6 can be varied only between approximately 30xc2x0 and 70xc2x0. This makes it difficult to move the nozzle unit 8 so as to reach sufficiently deep into an area such as below a bed where there is only a small gap above the floor, and is thus undesirable in terms of user-friendliness.
An object of the present invention is to provide an electric vacuum cleaner and a nozzle unit for an electric vacuum cleaner that offer improved userfriendliness in cleaning performed with the user taking a low position and in cleaning performed using an auxiliary nozzle. Another object of the present invention is to provide a compact and light-weight nozzle unit for an electric vacuum cleaner that offers improved suction efficiency.
To achieve the above objects, according to one aspect of the present invention, an electric vacuum cleaner is provided with:
a nozzle unit kept in contact with a surface to be cleaned for dust suction;
an extension pipe coupled to the nozzle unit;
a hose coupling the extension pipe to the body of the electric vacuum cleaner; and
a handle provided at an end of the extension pipe so as to be held by a user during cleaning, the handle being so formed that the angle of at least a portion thereof is variable relative to the extension pipe.
According to this arrangement, it is possible to change the angle of the handle provided at one end of the extension pipe coupled to the nozzle unit to a desired angle in accordance with the situation in which cleaning is performed, so that the user can hold the handle at the desired angle when moving the nozzle unit back and forth to do the cleaning.
According to another aspect of the present invention, a nozzle unit for an electric vacuum cleaner is provided with:
a body case having a nozzle open toward a surface to be cleaned, the body case having a substantially rectangular shape as seen in a plan view;
a first pipe that has a first air flow passage for allowing passage of a flow of air sucked in through the nozzle and that is coupled to the body case so as to be rotatable about a rotation axis parallel to the direction of the longer sides of the nozzle, the first pipe having a sliding portion that slides along the body case as the first pipe rotates, the sliding portion arranged inside the body case as seen in a plan view; and
a second pipe rotatably coupled to the first pipe, the second pipe having a second air flow passage that communicates with the first air passage.
According to this arrangement, the sliding portion of the first pipe is arranged inside the substantially rectangular body case as seen in a plan view so as to be slidable along the body case, and thus the first pipe can be inclined in the direction of the depth (i.e. in the direction of the shorter sides) of the nozzle unit. The air sucked in through the nozzle achieves dust suction by flowing through the first air flow passage inside the first pipe and then through the second air flow passage inside the second pipe, of which the latter can be inclined in the direction of the longer sides of the body case. By rotating the first and second pipes appropriately, it is possible to reduce the depth-direction width of the nozzle unit.